Patent Application
20140376426
This is the first application filed for the present application.
This application relates to machine type communications in general, and to a machine type communication aggregator apparatus and method, in particular.
The growing demands on mobile networks to support data applications at higher throughputs and spectral efficiencies has driven the need to develop Orthogonal Frequency Division Multiplexing (OFDM) based 4th generation (4G) networks including for 3GPP Long Term Evolution (LTE). A key objective with respect to deployment of OFDM 4G networks is to utilize a frequency re-use of one (denoted by N=1), or as close to N=1 re-use as is practical. A frequency re-use of N=1 implies that the cells in basestations transmit on all available time-frequency resources blocks (RBs) simultaneously. The need for higher throughputs in 4G networks, especially near the cell edge, combined with the constraint on the uplink link budget will necessitate the need for smaller cell sizes than is typically deployed for present 2nd generation (2G) and 3rd generation (3G) cellular systems. The addition of smaller cells can be deployed in a traditional homogenous cell splitting approach or in a more ad hoc heterogeneous approach in which pico cells or relay nodes are overlaid on an existing macro cellular network. For both a homogeneous and heterogeneous approach, the resulting interference limited system for N=1 deployment will not achieve the full potential capacity that the LTE standard can support without the implementation at the basestation and mobile terminal of one or more viable interference mitigation and or cancellation techniques.
Machine-to-machine (M2M) or MTC type devices are an emerging area of mobile communications that is expected to grow significantly in the next several years with an expected compounded annual growth rate (CAGR) of >25% in 2013.
It is desirable to find MTC solutions that ensure a clear business benefit to MTC UE vendors and operators for migrating low-end MTC UE's from GSM/GPRS to LTE networks.
The following references are incorporated herein by reference:
[1] 3GPP TS36.211, “E-UTRA Physical Channels and Modulation”, v11.1
[2] 3GPP TS36.216, “E-UTRA Physical Layers for Relaying Operation,” v10.3.
[3] 3GPP TR36.814, “E-UTRA Physical Layer Aspects”, v9.0.
According to one broad aspect of the present application, there is provided a machine-type-communication aggregator apparatus in a communications network, the communications network having wireless communication nodes including wireless basestations serving wireless device, at least one of the wireless devices being an aggregator node for aggregating machine-type-communications between machine-type-communication devices and machine-type-communication servers, the aggregator node being served by a serving wireless basestation. The machine-type-communication aggregator apparatus includes a node in the communications network, comprising: a communications interface for participating in at least one machine-type-communication involving the aggregator node; a processor configured to operate with the communications interface, the processor adapted such that the at least one machine-type-communication involving the aggregator node has the effect of limiting the impact that the machine-type-communication devices have on the uplink between the aggregator node and the serving basestation. In some embodiments, the at least one machine-type-communication is a portion of at least one of: a machine-type-communication aggregator start-up procedure, a procedure for a machine-type-communication device connection to an aggregator, an aggregator data collection procedure, a predefined mobility pattern based procedure with predefined machine-type-communication report times that are broadcast to the at least one machine-type-communication node, and a query based procedure for which machine-type-communication specific symbols are employed. In some embodiments, the node in the communications network is at least one of: a machine-type-communication device, the aggregator node, the serving basestation, an eNodeB, an MME, an Aggregator Manager, an S-GW, a P-GW, an MTC Management Server, and an MTC App Server. In some embodiments, the communications interface utilises at least one of: an aggregator radio access technology and a mobile network radio access technology. In some embodiments, at least one of the aggregator radio access technology and the mobile network radio access technology is LTE. In some embodiments, the communications interface uses at least one PCI of a serving eNodeB PCI and an aggregator PCI. In some embodiments, both the aggregator radio access technology and the mobile network radio access technology are LTE. In some embodiments, the aggregator radio access technology and the mobile network radio access technology use the different carriers. In some embodiments, the aggregator radio access technology carrier is narrow band and the mobile network radio access technology carrier is wideband. In some embodiments, the aggregator radio access technology is provided by one of a relay node and a mobile relay node. In some embodiments, the mobile relay node employs TDD with UL TDD configuration 0 and DL TDD configuration 5. In some embodiments, the aggregator radio access technology is one of WiFi and whitespace. In some embodiments, the aggregator radio access technology is WiFi using an SSID with a pattern. In some embodiments, the machine-type-communication aggregator start-up procedure includes at least one of the following: listening for other aggregators, RRC Conn, MTC Aggregator Notif, MTC Start Aggregation Service, MTC App Server List REQ, MTC App Server List RSP, RRC Disconn, and Aggregator Call Setup. In some embodiments, the procedure for a machine-type-communication device connection to an aggregator includes at least one of the following: MTC Conn Req, Authorize Server REQ, Authorize Server RSP, Authorize Device REQ, Authorize Device RSP, and MTC Conn RSP. In some embodiments, the at least one machine-type-communication include at least one of the following: MTC Data Report, Collection Period, RRC Conn, RRC Disconn, eMBMS broadcast predefined query times, MTC Data Report @T, MRN aggregated Data report, and CSI-RS, SR, grant @T. In some embodiments, the at least one machine-type-communication includes communication with machine-type-communication nodes using a predetermined pattern based on at least one of time and location. In some embodiments, the at least one machine-type-communication uses query based signalling based on coverage region of the machine-type-communication nodes. In some embodiments, machine-type-communication aggregator apparatus further includes a cache for storing the at least one machine-type-communication when the at least one machine-type-communication node is out of coverage. In some embodiments, the at least one machine-type-communication includes communication with machine-type-communication nodes using a default predetermined time assigned on eMBMS transmission. In some embodiments, the aggregator node is one of a root aggregator node and a node aggregator node.
According to another broad aspect of the present application, there is provide a machine-type-communication aggregator method in a communications network, the communications network having wireless communication nodes including wireless basestations serving wireless device, at least one of the wireless devices being an aggregator node for aggregating machine-type-communications between machine-type-communication devices and machine-type-communication servers, the aggregator node being served by a serving wireless basestation, the machine-type-communication aggregator method comprising: providing a node in the communications network, comprising and operating the node to limit the impact that the machine-type-communication devices have on the uplink between the aggregator node and the serving basestation. The node in the communication network includes a communications interface for participating in at least one machine-type-communication involving the aggregator node; a processor configured to operate with the communications interface, the processor adapted such that the at least one machine-type-communication involving the aggregator node.
Other aspects and features of the present application will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of a machine type communication aggregator apparatus and method in conjunction with the accompanying drawing figures.
Embodiments of the present application will now be described, by way of example only, with reference to the accompanying drawing figures, wherein:
Like reference numerals are used in different figures to denote similar elements.
The following abbreviations are used in this specification:
The present disclosure is applicable to the Machine Type Communication (MTC) domain where information is collected by MTC Application servers from many devices distributed over large areas. To be cost effective in deploying and managing the MTC devices, it makes sense to use Mobile Networks, which are also referred to as wireless networks in the present disclosure. This disclosure uses the terms wireless and mobile interchangeably such that a wireless device or node can be understood to be the same as a mobile device or node.
The number of MTC Devices connected to Mobile Networks is expected to grow significantly and they will impact the performance of the mobile networks. This disclosure uses MTC and M2M interchangeably such that an MTC Device or node can be understood to be the same as an M2M Device or node.
The present disclosure may allow a large number of MTC devices to be connected to the mobile network and to limit the impact on the mobile network.
The number of MTC wireless devices connected to the network may grow significantly. The mobile networks may have to cope with the increased number of devices and the cost of managing the devices. This cost may include managing more devices at MME level, allocating individual IP addresses for each MTC device, managing increased number of GTP tunnels.
Many MTC devices are reporting data infrequently which means that for every data report the device has to go through a full connection request followed by a disconnect request. This may make the control plane signalling cost for establishing connections and tear them down the main mobile network bottleneck.
It is desirable to find MTC solutions that ensure a clear business benefit to MTC UE vendors and operators for migrating low-end MTC UE's from GSM/GPRS to LTE networks. Such benefits may include:
The present disclosure focuses on MTC applications that require data collection from many devices spread on large areas. The MTC typical application anatomy is assumed to be composed of:
Referring to the drawings,
It is assumed that the MTC devices will have low throughput requirements and will communicate with the MTC application servers infrequently. The MTC devices will send data to the MTC servers at pre-determined time intervals (e.g. water meter sending data once a month to the application server; weather station sending data once an hour), on request from the MTC server (server requesting an unscheduled weather report) or when an event occurs (weather station reporting a power outage event).
The Mobile Networks (RAN+ECN) will have to cope with the increased number of MTC devices and with the increased signalling load that is characteristic for MTC devices. The introduction of MTC devices will change the ratio between the control data and user data and it will make the control signalling cost for establishing connections and tear them down the main Mobile Network bottleneck.
The present disclosure introduces a multi-tier network topology where some of the MTC devices will play a second role as data aggregators, consolidating data from several other nearby devices and hence reducing the impact on the mobile network. Different radio access technologies (RATs), like WiFi or LTE, can be used to aggregate data. Also different Radio Access Networks (RANs) can be used to connect the MTC aggregators to the MTC Application Server. Exemplary aspects of MACHINE TYPE COMMUNICATION AGGREGATOR APPARATUS AND METHOD are disclosed herein, including inter alia: (1) in the first aspect, the LTE Mobile Network that is used as the backhaul and LTE is also used for aggregator RAT; (2) in the second aspect, the LTE Mobile Network is used as the backhaul and WiFi is used for aggregator RAT; (3) in the third aspect, Mobile Relay based aggregation is used; and (4) in the fourth aspect, Multi-tier hierarchical aggregators are used.
Considering that a large numbers of MTC devices will be used in homes, like for example water meter, hydro meter, alarm systems, fridge, TV, temperature control, etc., it is reasonable to assume that there is a high probability that many of the MTC devices, belonging to different MTC applications, are located in the same proximity. Given the fact that part of the MTC devices connect to the servers at large time intervals and that they usually report low data volume, it would be desirable to aggregate the data from the devices before sending it to the servers in order to optimize the use of the mobile network.
This disclosure introduces the concept of the MTC aggregator that will collect data from MTC devices located in the aggregator's proximity and then it will forward the data to the MTC Application servers. In some embodiments, the MTC Application Servers will have the added responsibility of managing and authenticating the MTC devices, and will be identified as MTC Management Servers. In other embodiments, the MTC Management Servers and MTC Application Servers will be distinct.
The aggregator does more than just providing a proxy between the MTC devices and the MTC servers:
Although the MTC aggregator could be a separate network node, it is expected that one of the MTC device will assume a second role as a MTC aggregator while still performing its original MTC device role.
Different RATs, like WiFi or LTE, can be used between the aggregator and the MTC devices to collect data. Also different RATs can be used as backhaul to connect the MTC aggregators to the MTC Management Servers.
The Aggregator Manager (AM) 340 is a node in the ECN side of the mobile network that will manage the Aggregators 310i, j and will also contain the list of authorized MTC Management Servers 330a, b. The AM could be co-located with the MME. Note that the description of the MTC aggregator architecture above and as illustrated in
In some embodiments, the Aggregator will act like an LTE small-cell with a Closed Subscriber Group (CSG) made of only MTC devices. The Aggregator cell will not allow normal UEs to camp in the cell. There are 2 options:
To allow MTC devices to easily identify the aggregator cells, a subset of the cell IDs will be reserved for the aggregator cells.
Option 2 can be implemented with the aggregator being implemented as a Type 1b relay node that employs inband backhaul for communication with the serving eNB. Transmissions from the eNB to the aggregator can be configured as MBSFN transmissions and will be subject to the TDD eNB to relay (e.g. Un link) and relay to UE (e.g. Uu link) restrictions of Type 1b relay node transmissions as defined in [2].
The main advantage is that the MTC devices will use unlicensed spectrum to connect to the aggregator.
To allow MTC devices to easily identify the aggregator, in some embodiments, the Aggregator's WiFi SSID will have a special pattern: “MTC_A_<Aggregator_ID>”, where the Aggregator ID has several fields that will allow the MTC device to distinguish between aggregators, like a Mobile Network ID where the Aggregator is connected, a MTC Service Type ID that advertises what MTC devices should connect to the aggregator, etc.
Note that in addition to WiFi, other radio access technologies that are using unlicensed spectrum can be used, like for example the white spaces.
The procedures illustrated in
According to this aspect, mobile relay nodes assume the role of an aggregator MRN Aggregator 710. The mobile relay node (MRN) acting as an aggregator 710, can communicate with the MTC devices 10a, b, . . . n through either a predefined mobility pattern to receive MTC reports with low power transmissions at predefined times and physical locations, such as eMBMS broadcast predefined query 705 and MTC Data Report @T1, 2, . . . n 720a, b, . . . n shown in
A MRN acting as an aggregator can also be defined as a mobile aggregator that goes in and out of the Mobile Network coverage area. An example would be an Aggregator installed on a vehicle that collected information from different wireless sensors located in the vehicle. While the aggregator is connected to the mobile network, it can report data as usual, and when the aggregator goes outside the mobile network coverage, it will cache data received from the sensors until it re-establishes connection to the network.
For the predefined mobility approach, the times and locations of transmissions will correspond to an area of high geometry between the MRN and the MTC device to be communicated with. The MRN can set up a multicast broadband single frequency network (MBSFN) for all of the MTC devices to be aggregated within a given time interval. The predefined times for the MTC data reports can be preconfigured to a default value when the MTC device is authenticated in the network (not shown in the Figures), or assigned by an eMBMS transmission on the downlink from the MRN (as shown in
For both the predefined mobility and query based approaches of MRN to MTC communication, MTC devices within the MBSFN region can make use of MBSFN reference signals to detect on the DL, the presence of the MRN. Alternatively, the detection of good geometry can be achieved by use of MTC specific CSI RS transmissions to each MTC device in the MBSFN. Based on the measured geometry of the link between the MRN and the candidate MTC device, the MTC device will communicate the CQI to the MRN. Furthermore, based on the communicated CQI, the MRN will select the achievable MCS and provide the MTC device with a grant to communicate the MTC Data Report.
For TDD implementations of MRN aggregators, a further optimization can be achieved by employing TDD configuration 0 (as defined in [1]), on the uplink, which provides for 6 uplink subframes per frame and employing TDD configuration 5 (as defined in [1]) for DL transmissions, which allocates 8 DL subframes per frame.
Since an MTC device connected to an Aggregator can be itself an aggregator, a tree-like multi-tier topology of hierarchical aggregators can be build. The Aggregator that is connected to the mobile network is called the root aggregator, while the other aggregators in the tree are called node aggregators. Such a hierarchical topology is very useful for extending the area where MTC devices can be deployed beyond the coverage of the mobile network, like building basements, underground tunnels, etc. For node aggregators, it makes sense to use unlicensed spectrum (for example WiFi) for both the backhaul carrier and aggregation carrier but on different frequencies/channels. Root aggregators in some embodiments would benefit from using LTE for the backhaul.
The embodiments of the various aspects this disclosure may help the Mobile Networks to cope with the increase in the number of MTC devices. This is achieved by introducing MTC Aggregators that will collect data from the near-by MTC devices. Some advantages of this approach are:
Embodiments of aspects this disclosure may allow data gathering from a large number of MTC devices with limited impact on the Mobile Network.
The above-described embodiments of the present application are intended to be examples only. Those of skill in the art may effect alterations, modifications and variations to the particular embodiments without departing from the scope of the application, which is set forth in the claims.
